Minimising Noise Flanking Transmission to Pass Sound Testing
One way to reduce the chance of noise flanking transmission/s to pass the sound testing for Part E of Building Regulations is to carefully look at the acoustic details at the design phase of the project, as well as good planning and workmanship thereafter. Unfortunately, by simply specifying high performance wall and floor partitions between dwellings is no guarantee to a sound isolation and subsequently successful sound testing.
Sound travels along the path of least resistance between rooms, usually through any penetrations/air leaks or through rigid and poorly isolated connections in the structure itself, these routes are called noise flanking paths.
- Wide gaps below doors provide a flanking noise pathway.
- Air leakage around partition walls at the wall/ceilings junction.
- Sound leaking through ‘lightweight’ hollow-core doors.
- Through ductwork penetrations between two rooms or boiler cupboards placed back to back.
- Fixtures & Outlets – Light Switches, Telephone Outlets, and Recessed Lighting Fixtures (if penetrations have been cut back to back with the opposite dwelling under test)
- Poor sound isolation between floors, if subfloor wooden planking extend beneath the dividing floor partition and into an adjoining dwelling this will form a sound flanking pathway.
- Framing connections that include solid framing members passing between building areas such as oak beams where large old houses have ben subdivided.
- Poor isolation to partition abutments to adjoining walls, ceilings, floors
- Service penetrations behind back to back kitchens, such as soil stacks, waste and recessed pipework.
- Plumbing Chases – Junctures Between the Walls & Floor Slab Above or at the Exterior Wall Juncture (this should be filed with mortar etc. to add mass to this weakened area)
- Through Structural Steel (structural steel beams are often a major cause of noise transmission as plasterboard is often fixed directly to the steel without sound breaks)
- Dividing Floors – Through Floor and Floor Joist Space (if insulation has not been installed or direct fixing to joists without a drop ceiling below the partition under test)
- Dividing Ceilings – Above and Through the Ceiling Space (where an adequate acoustic break has not been carried on through the ceiling void).
- Recessed light fixtures that pass through the plasterboard and acoustic insulation.
- The wrong fixings used during the installation of resilient channel systems, i.e. drywall screws that are too long that penetrate into the ceiling joists.
- Window noise transmission due to poor performance glass etc.
- Door noise transmission due to the inclusion of lightweight hollow core doors, with large gaps to the bottom of the door threshold.
- On bathroom partitions, install drywall all the way to the floor before installing the bath and seal all plumbing penetrations through walls with a flexible sealant.
If the wall/floor partitions have poor isolation and can greatly reduce the effectiveness of soundproofing efforts and can lead to sound test failures. Even if your construction allows for ‘robust’ sound insulation ratings, it will be rendered useless, if sound can pass easily through service penetrations in the walls and floors or through lightweight doors.
APT Sound Testing offers both pre & post construction design solutions to achieve the required sound isolation requirements of Part E of Building Regulations.
We offer an acoustic onsite inspection service to ensure that the sound insulation elements are being installed as per manufactures guide lines and the quality of the workmanship is consistent with ‘best practice’ noise control procedures and we have the technical experience to help identify and rectify your soundproofing or noise flanking problem/s.
If you would like more information in regards to sound testing, please contact us at: firstname.lastname@example.org or call us direct on 07775623464